The Study of the Stress State in Girders Braced with Carbon Fiber

Abstract

Currently, composite materials are intensively used in the construction industry. The high physical and mechanical parameters of carbon fibers help improve the carrying capacity of structures without losing useful space and increasing the net weight of buildings. One of the key research goals is the study of the strain and stress conditions of structure elements depending on the bracing option using various composites to select the best option. This work deals with the study of the stress state of carbon fiber braced girder models and the assessment of the impact bracing has on the redistribution of stress in the workpiece. We used the photoelasticity method to study the stress state in the experiments. This method allows for a visual representation of the stress and strain state of the object under investigation. During the tests, we obtained stress fields in the models of girders made of piezooptical materials for two workpiece load options. Girder models used in the work were made of E2 plexiglass. We reviewed three carbon fiber bracing options for workpieces. The girders were tested for symmetrical lateral bending, namely for simple and three-point bending. We used the photoelasticity method to obtain interference bands representing the fields of top shear stresses in the workpiece. Using the stress fields, we analyzed the stress state of the girder models and assessed the bracing options in terms of reducing the stress in the region of tension.